Bottle treating plants of the kind with which the bottles are transferred according to the pitch between synchronously driven single machines by means of positive conveyors offer a number of essential advantages in comparison with known plants in which such single machines are driven independently from each other and which are connected with each other by slat band conveyors or the like. Minimum floor space and staff requirements as well as reduced noise level and high reliability in operation are especially worth mentioning. In order to achieve these advantages, however, it is important that the working conveying apparatus between the single machines not malfunction because of the presence of broken bottles.
With a known apparatus of the above-mentioned kind the bottles are supported by supporting surfaces on their bottom and are guided by guiding surfaces at the sides of their bodies. Consequently, only small glass fragments of broken bottles can fall through between the guiding and supporting surfaces. Larger fragments and partially broken bottles are transported by the pockets of the star wheel and the worm to the following machine in the same way as normal bottles. These large fragments can cause heavy damage and disturbances to the machinery. For example, broken off bottle bottoms and the like can easily get in between the worm and supporting surface and can cause damage to the worm.